Deep Residential Basement, Chelsea
description
Transcript of Deep Residential Basement, Chelsea
Deep Residential Basement, Chelsea
Toureen Plant
Toureen Contractors
City Basements
GroundworksRC Frames
Petrol Filling StationRefurbishment
Decommissioning
Demolition
Create a 585m2 basement around a Grade II listed Victoria Villa utilising the entire footprint of the plot including front, side and rear garden
To maximize internal space the basement is to be built partially under and around a tree protected under a tree preservation order
The Scope
Basement Plan
To accommodate a swimming pool within the basement and allow for the garden to be reinstated above, the basement was up to 8.5m deep
The deeper parts of the basement are to be formed in water bearing River Terrace Gravels
The Scope
The Challenges• The site is in a prime West London residential neighbourhood
sensitive to construction traffic
• The semi detached property shares boundaries with another semi detached villa, a school and a mews house to the rear. The semi detached villa adjacent being particularly sensitive to movement/deflections
The Challenges• Maximise internal space in the basement
• The basement had to be formed below and around a tree root protection zone. The TRPZ could not be compromised or the roots damaged
The Challenges
• Managing or excluding ground water from the excavation
• Offload and distribute materials around an irregular site
• Overlap construction of basement with refurbishment of existing property
• Tight programme and good value
The SolutionsTraffic management
• Purpose built gantry
• Made use of permanent works
The SolutionsTraffic management
• Designed to allow spoil removal, concrete pumping and lifting of plant
The SolutionsTraffic management
The SolutionsRetaining Walls
• Limit deflections by using propped Larrson sheet piles
• Increase space in the basement by using sheet piles over secant piled wall. Incorporate sheet piles into permanent works to reduce thickness of wall.
• Use of Larrsen sheet piles over zero piles to reduce propping requirements and limit deflection
The SolutionsRetaining Walls
• Silent and vibration less piling with minimum water jetting
• Temporary frame cut and installed to suit on site dimensions
The SolutionsRetaining Walls
The SolutionsRetaining Walls
• Existing house piled to limit settlement
• Contiguous retaining walls installed from inside of house
• Results of movement monitoring
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Diff to Base- LevelsTM1TM2TM3TM4TM5TM6TM7TM8TM9
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The Solutions Retaining Walls
• Install sheet piles outside boundary and extract.
The SolutionsTree Protection Zone
• Limit disturbance in TRPZ
The SolutionsTree Protection Zone
• Work in progress
• Offer better value with micro piles
The SolutionsTree Protection Zone
• Reduce plant size and space requirements
The SolutionsTree Protection Zone
• Make use of permanent work piles as king posts
The SolutionsTree Protection Zone
The SolutionsManaging Groundwater
• Appreciating the problem
The SolutionsManaging Groundwater
The SolutionsManaging Groundwater
The SolutionsManaging Groundwater• Forming cut off walls to stem water
flow
The SolutionsManaging Groundwater• Deep drainage sumps
The SolutionsManaging Groundwater
• Pumping and disposal
The SolutionsProgramme
• Top down vr bottom up
The Solutions Programme
• Tower Crane
The Solutions Programme • Removal of soil
The Solutions Programme • Removal of spoil
The Solutions Programme
• Working inside and outside the property simultaneously
The Solutions Programme• Support of front portico and rear extension on temporary piles
Summary • Sequence of works allows work inside and outside of property simultaneously
• Choice of retaining walls, temporary works, tower crane and gantry improve safety, efficiency and productivity
• Bottom up approach allows better access, logistics and working conditions
• Alternative temporary works around TRPZ
• Shorter programme lead to better value
Summary • Quality work executed by skilled operatives and tradesmen